Michael's brother, Rhett Hutchence, is convinced his brother would have provided for his daughter. Source: Instagram

It was the mystery looming over Tiger Lily Hutchence Geldof's low-key 18th birthday celebrations on July 22 - just where are the missing millions she’s due to inherit from her tragic rock-star father Michael Hutchence?

"He would have hated this outcome to his will," claims the charismatic singer’s younger brother Rhett, who fears the puzzle may never be unravelled.

"Michael worked very hard for what he achieved."

The legendary INXS frontman was widely believed to be worth up to $30 million when he hanged himself at Sydney’s five-star Ritz-Carlton hotel in 1997.

Yet when Michael's estate was finally settled in 2005 - five years after Paula’s death from a heroin overdose, with four-year-old Tiger found playing beside her body – the executor’s report advised his family there was no money for those due to inherit.

Michael, it appeared, was technically bankrupt – although he certainly did not foresee that outcome when he revised his will a year before his death, leaving the first $500,000 of his estate to Greenpeace and Amnesty International, and the rest divided 50/50 between Tiger and his family.